There is conventionally known a driving assistance apparatus, which detects an obstacle using such obstacle sensors as a camera or sonar provided in a vehicle and reports the presence of the obstacle.
Patent literature 1 discloses a driving assistance apparatus, which determines the presence or absence of an obstacle around a vehicle based on output signals of clearance sonars provided in a front portion and a rear portion of a host vehicle, and reports the presence of an obstacle using buzzer sounds when detecting a close approach to the obstacle in proximity of the host vehicle.